All of the Disney resorts are open to the public. You can dine at any of the restaurants, walk around and explore, shop, and use the recreational facilities (except for the pools). All resorts are outside of the theme parks, so you don't need a ticket to access any of them. You can use Disney's monorails, boats and buses to travel around Disney World.
Because there are so many resorts (and resort restaurants) and they're spread out over a 40+ mile area, you'll want to figure out which restaurants you'd like to try, and then figure out how to get there. As mentioned above, only three resorts are on the monorail line. There are several fine restaurants in the Epcot area resorts, and you can catch a bus from MK to those resorts. Lots of really fun places to eat at Disney Springs, too.